don't fill in the sides--leave a little space--you don't want to set up a hard spot with the sides--everything else sounds good.
I use a 1.5 tip for primer and a 1.3 Satajet gun for base clear and single stage urethanes. To get the proper pressure readings you need HVLP air...
It will eventually set up. You can try and cover the area with plastic wrap. The cover may allow it to setup hard. A heat gun used judiciously...
Please be careful spraying 2 part urethanes, they can ruin your liver if you don't wear a good respirator. You can also buy a fisheye eliminator...
The sheer force on styrene panels is very low. I would advise against it. There are better tried and true options out there.
Even at 1%, it will eventually cure. It may take a long time but it will set up eventually.
I would cut the transom off from the outside. To cut it out from the inside would destroy the inner hatches. Cut the transom all the way around...
If you use an unwaxed resin, you can bond to it as long as it remains tacky, usually 30 days. Waxed resin always needs a mechanical bond. Cabasil...
Find a free boat that needs work. Spend the 200 bucks on fixing the transom and stringers. I know of a few in my area that would fit the bill.
A house rarely sinks and goes down in value.
A carb that sits for 10 years, needs a rebuild job, at least the float and needle set. Check the antisyphen valve at the tank. Boats should not...
styrene first, then 1 percent mek. this will allow a slower cure for penetration.
What type of boat? and power?
How much do you like the boat? Its a lot of work. The stringers are probably gone and the transom too. Major work, but can be done. Lots of...
You can thin down 5 percent, no more. This should allow for a better penetration into the wood.